The present invention relates to a group forming device for cigarette packing machines.
In particular, the present invention relates to a group forming device for cigarette packing machines; each group comprising a number of cigarettes arranged in at least two adjacent layers, wherein the cigarettes in one layer are offset in relation to those in the other layer; and the device comprising at least one outlet for the groups; each outlet comprising a number of side by side channels for feeding respective rows of cigarettes transversely in a given direction; an end wall closing and crosswise to the channels; and a lateral opening adjacent and crosswise to the end wall.
In general, the aforementioned groups consist of twenty cigarettes arranged in two layers of seven and a third layer of six cigarettes. In rigid packets, the six-cigarette layer is normally an outer layer with the cigarettes offset in relation to those of the intermediate layer, the cigarettes of which are aligned with those of the other outer layer. In soft packets, on the other hand, the six-cigarette layer is normally the intermediate layer, the cigarettes of which are offset in relation to those of both the outer layers.
On known cigarette packing machines, group forming devices of the above type constitute the output portion of the input feedbox of the packing machine, and normally comprise three side by side outlets which, as described for example in U.S. Pat. No. 4,700,825, are associated with respective lateral push devices for feeding respective layers of cigarettes into successive pockets of a pocket conveyor extending to the side of the outlets. That is, each pocket is supplied by each outlet with a respective layer, and all three outlets cooperate in forming each group.
Known group forming devices of the above type present a number of both technical and functional drawbacks. Firstly, forming each group in successive layers involves the use of a large number of push and guide members for successively feeding the layers into each pocket and maintaining them in an orderly position inside the pockets as the groups are formed. Secondly, the cigarettes in the layers following the first are fed into the respective pockets on the conveyor by sliding them over the cigarettes in the layer underneath, thus resulting in friction and possible damage to the cigarettes.